1. Field of the Invention
The present invention relates to a sludge removing device for removing a sludge mixed in a molten salt-bath solution, and a method of manufacturing such a sludge removing device.
2. Description of the Related Art
Salt-bath softnitriding devices have been used to case-harden an iron-base metallic parts such as automobile parts including crankshafts or the like. Specifically, a salt-bath softnitriding device case-hardens a iron-base metallic part when the iron-base metallic part is immersed in a salt-bath solution in which a salt-bath agent has been heated and molten.
As the case-hardening process continues, the amount of a sludge mixed into the molten salt-bath solution increases tending to degrade the quality of the processed iron-base metallic part. Various methods have heretofore been proposed to remove the sludge from the salt-bath solution. According to one known method, a pot of metal mesh or the like is placed in a salt-bath furnace, the molten salt-bath solution is stirred to float the sludge, and after the stirring has been stopped, the sludge settled on the bottom of the pot is taken, together with the pot, from the salt-bath furnace.
However, the above conventional method is problematic in that the efficiency of the salt-bath softnitriding device is low because the salt-bath softnitriding device is out of operation while the sludge is being removed from the salt-bath furnace.
It is a general object of the present invention to provide an economic sludge removing device which lends itself to repeated use, and a method of manufacturing such an economic sludge removing device.
A major object of the present invention is to provide a sludge removing device which is capable of efficiently and reliably removing sludge from a molten salt-bath solution, and a method of manufacturing such a sludge removing device.